1. Field of the Invention
This invention relates to a data communication system comprising a mobile telephone capable of communicating with a communication apparatus via a network, and an image processing unit capable of data communication with this mobile telephone and of image output. The invention relates further to the mobile telephone and image processing apparatus constituting this image communication system, and to a method of controlling the mobile telephone and image processing unit.
2. Description of the Related Art
The proliferation of mobile telephones [inclusive of portable telephones compliant with the PHS (Personal Handy Phone System) standard] and personal digital assistants (PDAS) has made it possible to send and receive voice and image data regardless of time and place. Standards for end-to-end communication between mobile telephones and personal digital assistants also are being instituted in stages.
Not only voice data but also various other data such as image and text data can be transmitted to a mobile telephone. Though a mobile telephone can receive this voice data and enable voice to be heard, often these telephones do not have the capability to receive the image data and display an image represented by this image data. Mobile telephones that can receive the text data and display the text represented by this data have been realized but the number of characters that can be displayed is small.
When data is transmitted to a mobile telephone, an alert tone indicative of the incoming call is issued by the mobile telephone irrespective of whether the incoming data is voice, image or text data. When voice data is received, it is possible to converse using the mobile telephone. When data other than voice data, e.g., image data, is received, however, often the image cannot be displayed even if the mobile telephone is operated in response to the incoming-call alert. Depending upon the received data, therfore, it is necessary to operate a personal digital assistant that is capable of displaying an image.